Mike, please clarify these specs:
Oven Dimensions 29½ x 141/8 x 181/8
If that 14 1/8" dimension is either depth or width, a 16" pizza is out of the question.
Measure your oven shelf. Take special notice of any lips that might get in the way of the stone and subtract those from the dimensions.
Greek and grandma styles generally require slightly lower temps than NY, so, if a stone can do NY, you can always turn the oven down for Greek and grandma.
For NY in a home oven with either convection and/or a broiler in the main compartment, 1/2" steel plate is ideal. From the soapstone you're working with, it's a step up in conductivity and thermal mass, both of which will trim baking time off the undercrust. Combined with convection and/or broiling (for a fast top bake), you can achieve ideal NY bake times of 4-5 minutes @550 deg.